Tubular members for a variety of uses (e.g. conduits, shafts for sporting equipment etc.) are often made from composite materials.
For example, over the years, advancements in material technology have led to increased sophistication in the manufacturing and performance of hockey sticks. Traditionally, hockey sticks were manufactured primarily of wood with a fiberglass covering on the blade portion. The wood stick comprised a solid shaft, either a single piece of wood or a sandwich of multiple layers of wood. Solid shafts are typically very durable but suffer somewhat from relatively high weight and limited flexibility.
Through the use of advanced material technologies, modern hockey sticks are often manufactured using a wide variety of materials. In addition to the aforementioned wood and fiberglass, newer materials including lightweight metals, such as aluminum, and high performance polymers and composite materials. For example Kevlar, RTM (resin transfer moldings), graphite, ABS (acrylonitrile butadiene styrene), carbon fiber and ceramics are being used either individually or in combination.
Using these new materials, manufacturers of hockey sticks, have been able to alter hockey stick performance to adjust and tune stick characteristics such as weight and stick flex.
One way in which these new materials have affected stick construction is through the development of hockey sticks having hollow shafts. U.S. Pat. No. 6,241,633; Hockey Stick Shaft and Method of Making Same; Conroy; issued 5 Jun. 2001, is an example of a method for making such a hockey stick.
Hockey sticks with hollow shafts can be manufactured of any of the aforementioned materials and can be either one-piece designs, or they can include removable/replaceable blades and shaft extensions to vary the overall stick length.
One drawback with hollow shafts is that the shafts are more likely to break in use, as compared to hockey sticks with conventional solid shafts (for which the blade was more likely to break than the shaft). As hollow shafts and modern stick designs often have a significant replacement cost, shaft breakage can lead to significant warranty and service issues for suppliers, as well as frustration on the part of consumers.
Examples of apparatus and methods for repairing hockey stick shafts are described in: U.S. Pat. No. 7,108,618, Apparatus and Method for Repairing a Hockey Stick Shaft, Frischmon et al., issued: 19 Sep. 2006; and Canadian Patent No. 2,561,446, Support System For A Single- Or Multi-Piece Hollow Object.